In general, an electronic control apparatus such as an ECU, which electronically controls various types of devices, is equipped in a vehicle. The electronic control apparatus receives information from sensors or switches that are installed at each part of the vehicle. The electronic control apparatus serves to perform various electronic controls for promoting improvement of a riding quality and safety of the vehicle or providing various items of convenience to a driver and a passenger by processing the received information.
For example, the electronic control apparatus such as the ECU, which controls states of an engine, an automatic transmission, an anti-lock brake system (ABS), and the like in the vehicle using a computer, also serves to control all parts in the vehicle, such as a driving system, a braking system, and a steering system as well as the automatic transmission as the vehicle and the computer have been developed in terms of performance.
The electronic control apparatus such as the ECU has a structure that includes a case which includes an upper cover and a lower base, a printed circuit board (PCB) which is accommodated in the case, a connector which is coupled to a front end of the PCB so as to be connected to an external socket, and the like.
The cover and the base are assembled together with the PCB while covering the PCB, and particularly, the connector, which is interposed between the cover and the base when the cover and the base are assembled, forms a sealing structure with the cover side and the base side.
Heating elements are provided on a top side of the PCB, and a heat radiating pad is attached to a bottom side of the PCB. The cover and the base are fastened by a screw.
The heating elements such as capacitors, transistors, or various types of ICs are mounted on the top side of the PCB, and heat is generated from the elements depending on operations of the elements. In this case, the heat radiating pad having excellent thermal conductivity is attached to the bottom side of the PCB so as to radiate the generated heat to the outside. When the heat radiating function of the heating elements is not smoothly performed, the element may be abnormally operated and durability of components may deteriorate due to the generated heat, and the electronic control apparatus may be abnormally operated.